Electronic Preprints

There are currently 2 electronic preprints awaiting publication. They are listed below in reverse chronological order.

2024

Title: Depth-resolved Characterization of Meissner Screening Breakdown in Surface Treated Niobium
Author: E. Thoeng, M. Asaduzzaman, P. Kolb, R. M. L. McFadden, G. D. Morris, J. O. Ticknor, S. R. Dunsiger, V. L. Karner, D. Fujimoto, T. Junginger, R. F. Kiefl, W. A. MacFarlane, R. Li, S. Saminathan, R. E. Laxdal
Abstract: We report direct measurements of the magnetic field screening at the limits of the Meissner phase for two superconducting Nb samples. The samples are processed with two different surface treatments that have been developed for superconducting radio-frequency cavity applications - a "baseline" treatment and an oxygen-doping ("O-doping") treatment. The measurements show: 1) that the screening length is significantly longer in the "O-doping" sample compared to the "baseline" sample; 2) that the screening length near the limits of the Meissner phase increases with applied field; 3) the evolution of the screening profile as the material transitions from the Meissner phase to the mixed phase; and 4) a demonstration of the absence of any screening profile for the highest applied field, indicative of the full flux entering the sample. Measurements are performed utilizing the -detected nuclear magnetic resonance (β-NMR) technique that allows depth resolved studies of the local magnetic field within the first 100 nm of the surface. The study takes advantage of the β-SRF beamline, a new facility at TRIUMF, Canada, where field levels up to 200 mT are available parallel to the sample surface to replicate radio frequency (RF) fields near the Meissner breakdown limits of Nb.
: arXiv:2405.05451 [cond-mat.supr-con]

2020

Title: Digging into MUD with Python: mudpy, bdata, and bfit
Author: D. Fujimoto
Abstract: Used to store the results of μSR measurements at TRIUMF, the Muon Data (MUD) file format serves as a useful and flexible scheme that is both lightweight and self-describing. The application programming interface (API) for these files is written in C and FORTRAN, languages not known for their ease of use. In contrast, Python is a language which emphasizes rapid prototyping and readability. This work describes three Python 3 packages to interface with MUD files and analyze their contents: mudpy, bdata, and bfit. The first enables easy access to the contents of any MUD file. The latter two are implemented specifically for the implanted-ion β-detected NMR (β-NMR) experiment at TRIUMF. These tools provide both an API and graphical user interface (GUI) to help users extract and fit β-NMR data.
: arXiv:2004.10395 [physics.data-an]